U.S. patent number 4,850,046 [Application Number 07/113,826] was granted by the patent office on 1989-07-18 for infrared transmitter of coded message having fixed code and large number of combinations.
This patent grant is currently assigned to Neiman. Invention is credited to Patrick Philippe.
United States Patent |
4,850,046 |
Philippe |
July 18, 1989 |
Infrared transmitter of coded message having fixed code and large
number of combinations
Abstract
An infrared transmitter of coded message is provided having a
fixed code and large number of combinations particularly but not
solely for use in the automobile industry. The transmitter
comprises a series programmable electronic memory (1), the content
of which is addressed by a pulse transmitter (2), an oscillator or
timer, the content of the memory (1) being supplied to a pulse
generator (3) supplying an amplifier (4), the output of which is
transmitted to a transmitter diode (5), the content of the memory
(1) being supplied, in addition, to an end of message blocking
device (6) controlling the reading pulse transmitter (2).
Inventors: |
Philippe; Patrick (Jambville,
FR) |
Assignee: |
Neiman (Courbevoie,
FR)
|
Family
ID: |
9340357 |
Appl.
No.: |
07/113,826 |
Filed: |
October 29, 1987 |
Foreign Application Priority Data
|
|
|
|
|
Oct 30, 1986 [FR] |
|
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86 15110 |
|
Current U.S.
Class: |
398/189; 398/106;
398/161; 398/184 |
Current CPC
Class: |
G08C
19/28 (20130101) |
Current International
Class: |
G08C
19/16 (20060101); G08C 19/28 (20060101); H04B
009/00 () |
Field of
Search: |
;455/603,608,617,618
;340/825.54,825.56,825.04,825.06 ;358/194.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Griffin; Robert L.
Assistant Examiner: Van Beek; Leslie
Attorney, Agent or Firm: Wray; James Creighton
Claims
I claim:
1. An infrared transmitter of coded message having a fixed code set
therein, comprising, a series programmable electronic memory, the
content of which is addressed by a reading pulse transmitter, the
content of the memory being supplied to pulse generator supplying
an amplifier, the output from which is supplied to a transmitter
diode, the content of the memory being supplied, in addition to an
end of message blocking device controlling the reading pulse
transmitter, wherein the blocking device comprises a gate which is
supplied from a capacitor which is supplied via a resistor, and the
transmitted message is terminated by a series of binary 1 bits
which cause the capacitor to charge, thus causing the gate to flip
and block the pulse transmitter.
Description
BACKGROUND OF THE INVENTION
This invention relates to an infrared transmitter of coded message
having a fixed code and large number of combinations.
Coded message transmitters are used, for example, for the remote
control of security systems, in particular in the automobile
industry. The coding of these transmitters is, as a rule, effected
by cutting certain transmission paths of a circuit. This mechanical
coding, which is visible, is easy to read visually, and in
addition, the number of combinations is limited.
OBJECT OF THE INVENTION
An object of the present invention is to eliminate these
disadvantages of the known transmitters.
SUMMARY OF THE INVENTION
According to this invention an infrared transmitter comprises a
series programmable electronic memory, the content of which is
addressed by a pulse transmitter, oscillator or timer, the content
of the memory being fed to a pulse generator supplying an
amplifier, the output from which is fed to a transmitter diode, the
content of the memory being fed also to an end of message blocking
device controlling the reading pulse transmitter.
In the transmitters according to this invention, the code is
contained in an electronic programmable memory, that is to say this
code cannot be read visually. In addition, the number of
combinations depends only upon the capacity of the memory used.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be better understood from reading the following
description, prepared with reference to the attached drawing, in
which:
FIG. 1 is a block diagram of a transmitter according to this
invention, and
FIG. 2 is an electronic circuit of the transmitter of FIG. 1, for
one example of embodiment.
DESCRIPTION OF PREFERRED EMBODIMENT
The device comprises a memory 1 of the series programmable type,
reading of which is controlled by the pulses transmitted by a
reading pulse transmitter 2, an oscillator or timer. The content of
the memory 1 is fed to a pulse generator 3. The generator 3
supplies an amplifier 4, which supplies a transmitter diode 5. The
content of the memory 1 is supplied also to an end of message
blocking device 6, which controls the transmitter 2.
For defining one transmitted bit, 8 memory bits are used. The
transmitted bit comprises one synchronization bit and one data bit
0 to 1. For blocking the system at the end of transmission, the
last bit transmitted (comprising 8 bits) has all its bits
positioned at 1, which enables the capacitor C (FIG. 2) of the
blocking device 6 to be sufficiently charged for the voltage at the
input to the gate IC.sub.1 to cause this gate to flip and block the
oscillator 2. The system will not be able to transmit again until
its supply has been cut or the capacitor C has been discharged,
depending upon the type of memory used.
* * * * *